Sudden is a word that is often used to describe something that occurs unexpectedly or abruptly. However, there are many synonyms for sudden that can be used to add variety and interest to your writing. Some synonyms for sudden include instantaneous, unexpected, immediate, abrupt, unforeseen, and spontaneous. Each of these words has a slightly different meaning, but they all convey the sense of something happening quickly and without warning. By using synonyms for sudden, you can add nuance and depth to your writing, and create a more captivating and engaging narrative.